Semimechanical telephone-exchange system



J. L. MCQUARRIE ET AL SEMIMECHANICAL TELEPHONE EXCHANGE SYSTEM ug.. l

Original Filed Feb. 5, 190'? '7 Sheets-Sheet 1 ug., l2 M240 Lffflr J. L.MCQUARRXE ET AL SEMIMECHANICAL TELEPHONE EXCHANGE SYSTEM Original FiledFeb. 5, 1907 '7 Sheets-Sheet 2 u., l 11924., mmh@ J. L.. MCQUARRIE ET m.

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.11. L. MQQUARRHE ET AL S EMIMECHANICAL TELEPHONE EXCHANGE SYSTEMOriginal Filed Feb. 5, 190'? 7 Sheets-Sheet 5 v R5 gg 4 u@ m wm., mm@

J. L. NICQUARRIE ET L.

SEMIMECHANTICAL TELEPHONEEXCHANGE SYSTEM Original Filed Feb. 5, 190'7 '7Shams-Sheety G VII) 77 Q 7 Wm 2 t 4 MM f @A U h 8 Y S d. .wm .Mw e h WST S7 Y s H/ ...ww NM1 Tw, EXS EE. D E l. e mmv. H Aww l ULi Qmp .C www.,.Cm Lm Ai Hr CO E M 1 M E s Patented Aug.. l2, i924.

JAMES L. EICQUARRIE, OF CHICAGO, ILLINOIS, AND ALBERT M. BULLAR'D,OF`NEW YORK, N. Y., ASSIGNORS, BY MESNE ASSIGNMENTS, TO WESTERN ELECTRICCOM- PANY, INCORPORATED, A CORPORATION OF NEW YORK.

SEMIMECHANICAL TELEPHONE-EXCHANGE SYSTEM.

Application led February 5, 1907, Serial No. 355,884.' Renewed April 22,1909. Serial No. 491,601.

To all whom it may concern:

Be it known that we, JAMES L. MCQUAR- um, of Chicago, Cook County,Illinois, and

ALBERT M. BULLARD, of New York, New York County, New York, citizens ofthe United States, have invented a certain new and useful Improvement inSemimechanical Telephone-Exchange Systems, of which the following is afull, clear,.concise, and exact description.

Our invention relates to a telephone system wherein the operator answersa call in the usual way by uniting her connecting circuit with thecalling line, and mechanical switching mechanism completes theconnection by uniting the connecting circuit with the called line, andhas for its object to provide an rimproved arrangement of circuits andapparatus for facilitating the work of the'operator in completingconnections between subscribers lines.

Our invention relates more specifically to a semi-mechanical telephoneexchange system in which means is provided whereby an operators senderor controlling` device `is adapted t0 be associated with one of aplurality of connecting circuits when such connecting circuit is takenfor use.

In accordance with one feature of our invention, we provide means, inconnection with a plurality of connecting circuits for interconnectingsubscribers lines, whereby a number of senders or controllingdevices,less than the number of connecting circuits, will suflice for theexpeditious and accurate operation of the system, and means whereby aconnecting circuit, upon being taken for use, will have automaticallyassociated therewith a sender or controlling device to control the lineselection, and upon the complet-ion of such selection have such senderor controlling device dissociated therefrom.

Our invention further involves meansv whereby one of a plurality ofsenders or controlling devices will be maintained normally accessible toa plurality of connecting circuits, means whereby upon the taking of oneof the connecting circuits for use the sender or controlling device willbe approf priated thereto and a second sender or controlling devicerendered accessible to the re.- maining connecting circuits, meanswhereby if a second connecting circuit is taken for use before the firstsender or controlling device has completed its operation the secondsender or controlling circuit will be appropriated by the secondconnecting circuit and means whereby the senders or controlling deviceswhen they have completed their operation will be again restored tocondition ready to serve some other connecting circuit.

The present invention is capable of especially advantageous use inconnection with the telephone system forming the subjectmatter of ourapplication for patent for telephone exchange system, Serial No. 336,401tiled September 27th', 1906, wherein the operator answers a call in theusual manner by uniting her connecting circuit with the line of thecalling subscriber by means of a connection switch, and is provided withmechanical switching mechanism for completing the connection of herconnecting circuit with a desired line, said switching mechanism beingcontrolled by sending apparatus adapted to be set by the operator tocause the said switching mechanism to automatically unite saidconnecting circuit with the called line.

In the said system, a single sending apparatus is provided to serve anumber of connecting circuits. Under ordinary traffic conditions, suchsingle sending apparatus is adequate, but there are times when callscome too fast to enable one sending apparatus to serve the severalconnecting circuits, inasmuch as the sending apparatus must necessarilyoccupy a denite interval of time in controlling the selective operationsof the switching mechanism.

In accordance therefore with the present invention, a number of sendingoutfits or senders may be provided for use by a given group ofconnecting circuits; each connecting circuit is provided with asender-seizing switch by which'one of the sending outfits may beappropriated to the use of that connecting circuit in establishing aconnection, and means are provided whereby, during the use of the senderso taken, another sender may be automatically made available to beseized by any other connecting circuit of that group which may be putinto service before the first sender has finished its work.

More specifically, in the particular form of ourinvention at presentcontemplated, an automatic transfer switch is associated with thesender-seizing switch and determines which of the sets of sending'apparatus shall be connected to the terminals of said seizing switch.Normally, one set of sending apparatus will be available for theseizingswitches of all the connecting circuits of the group, but uponthe operation of any such seizing switch, the transfer-switches of allthe :other Iconnecting circuits will be actuated `-to .bring another setof :sending apparatus into operative relation to the remainingseizingswitches, wfhile locking out Vsaid 'seizing switches 4'from thebusyset. When the -firstrsender lh'as finished its work it isautomaticallyffreed from the connecting circuit ywith 'which it has beenoperating, and is again made available to be seized by 'other:connecting circuit of lthe group.

'lV'e Will describe our invention more yparticularly by reference totheaccompanying drawings representing the application of our invention to amechanical telephone sys- -tem, reserving, however, for the appendedclaims, a .statement ofthe parts, improvef-ments and coinloinationswhich we regard `as novel with us. f

lIn the drawings, Figs. l, 2, 3,v v4, 5, 6 and 7 representvdiaglrammati'cally .a 'calling and a called subs'cr'i'hers line, withtwo operators connecting circuits "and ltwo sending mechanisms, togetherwith thefmechanical switching mechanism 'associated with one ofsaid'connecting circuits.

These lsheets of drawings, `if placed Vedge to ledge y-inthe rorder ofFigs. 7,6,.5, 1, 2, 3,and 4 form a single diagram, the lines ywhich areextended Ito theedge of each sheet being continued on-'the :succeedingsheet.

We will iirst describe the circuits and apparatus which we .haveprovided forenabling a connecting -cir'cuit to pick up an idle sendingapparatus mechanism.

Y' Fig. $1 shows two Vconnecting `circuit-s or cord circuits I' and IIIvof the group which any vis to :be handled `by `a given operator, alsoshow-'s the two sets 'of sender leads or wires extending from theprimary and subsidiary senders. v'The complete mechanism of the primarysendingfapparatus is vshown in Figs. 5, 6 and 7, lout only va portion'of the apparatus of'thesubsidiary senders is indicated, to 'avoidneedles duplication. For brevity, we may hereafter refer 5to the primaryand subsidiary senders as sender A and sender YB, respectively, Abutthese letters are vnot usedV 'asreference-characters on the drawings. Y.

Each connecting circuit has associated with it a sender-seizing relay31, which is adapted when excited to interrupt the continuity of theconnecting conductors 8 and 9v and to connect the extensions thereof toa pair `of leads 'from one of the sending outtits,-the particular senderthus seized being determined by a transfer relay 21 also associated witheach connectin g circuit. Thus the leads 41 and' 44 of the primarysender are normally connected through wires 505 and 506 through backcontact of the transfer relay to armatures 492 and 493 thereof and bywires 502 and 504 to the armatures 39 and 40 respectively of thesender-seizing relay, which when attracted engage springs 42 and 45,-andthus vextend the circuit to the connecting wires 8 and 9. The leads 41aand 44a of the subsidiary sender are connected to front 'contacts of thearmatures 492 and y493 of the transfer relay, so that wh'cn saidtransfer-relay is excited, the armatures or, terminals 39 and 40 of thesender-seizing relay Vare connected to said subsidiary leads 41a and 44ainstead of the primary leads 41 and 44.

Each opcrators connecting circuit is provided with a key 19 for tying` asending keyboard to such circuit. The contact spring 20 of eachconnecting circuit key, whose normally-open co-ntact anvil is connectedby conductor 22 to the. free` pole ol" battery 58, is connected with a.conductor A28, which leads through armature 29 and yback contact ofrelay 30, winding of relay 31, arma-ture 491, and back contact of relay21 to the common wire 495, which leads to the sending keyboard A, saidlconductor passing through the winding of a. `controlfling relay -26 'ofsaid keyboard, through the 4armature 3)2 and back contact of a relay 334to earth.

The front contact of armature` 491 of relay 21 of each connectingvcircuit is connected with fa conductor 496, which leads to the commonwire 495*1 extending to the 'keyboard B, and there passing through thecontrolling relay 26 of said keyboard to earth. Thus when armature 491of relay 21 'of 'either vcord circuit rests against its -ba'ck contact,'the operation of spring` 20 of key 19 yof vsuch connecting circuit willvcause 'the operation ofthe controlling relay V26 of the A board,completing for said relay a circuit 22, 28, 495, including batt/ery 58;while if the armature 491 of relay v21 of either connecting circuit isin engagefme-nt with its front contact, and key 19 of such connectingcircuit be operafted, a

circuit 22, 28` 496, Y495 will be completed for thecontrolling relay 26of the B board.

'lll-re relay 31 .in the circuit of the controlling relay 26 of thesending apparatus taken for use is 'adapted when energized to complete alock-ing circuit for itself and relay 26 independently of key 19 frombattery 17, in the circuit 18, 35,495 (or 495a according to the keyboardsecured) said locking circuit remaining intact until the selected boa-rdhas completed its Work.

The4 relay 21 of each connecting circuit is provided With a Winding 497included in a conductor 499, leading from the back contact of armature500 of relay 31, (which armature is connected With the tree pole of abattery 59) through the armature 24 and front contact of the controllingrel-ay 26 of the A board to earth. Thus Whe-n said armature 24y ot' thecontrolling` relay 26 is attracted, due Ato the operation of a key 19ant one connecting circuit to associate keyboard Atherevvith, acircuit-499 Will be completed at the other connecting circuit or circuits,including 'the Winding` 497 of relay 21, Which will thereupon attractits armatures, armature 491 causing the controlling relay 26 of keyboardB to be operated When the key ot' such other connecting' circuit shallbe subsequently actuated, such circuit being by Way ro-f'conductors 22,28, 496, 495*1 as previously described. The Winding 498 of relay 21 ofeach connecting` circuit is included` in a conductor 501 Whichleads fromthe front Contact ol' armature 500 of relay 31, armature 494 and frontcontact ot relay 21, Winding 498 of said relay 21, to earth, so thatwhen the relay 21 of an idle connect-ing'- circuit has been operated, asbetore described, @to bring the keyboardB into position to serve suchconnecting` circuit, and the key 19 of such connectingy circuit issubsequently operated to energize relay 81` a. locking circuit Will becompleted tor relay 21 trom the tree pole of the grounded battery 59,conductor 501, Winding 498, of relay 21, to earth, said locking,`circuit remaining); int-act until the keyboardv B has linished itsvvork, in order to insure the continued association of keyboard Bf Withsuch other connecting circuit, regardless vot the condition of the boardA. i

The relay 21 of each connecting-circuit is provided With armatures 492`493, connected by conductors 502, 504 With the 'armatures 39, 40,respectively, of relay 31, said armatures 39, 40 being adapted Whenenergized to separate tivo sets ot springs 42, 48 and 45, 46,respectively, included in the link conductors 8, 9, -fsaid armatures 40,engaging springs 42, 45, respectively, which are directly connected withthe portion of t-he strands 8. 9 leading to the switching mechanism. Theback contacts ot armatures 49,2` 493 are normally connected bycmiductors ,505, 506, respectively. Wiltli local wires 41, 44 leading tothe A, boarcb and when said relay 2l ot a connectinfI-circuit isoperated, While the other connecting-circuit is usingselector-controlling,mechanism A, the armatures 492,493 ot said relayWill be connected with conductors 507, 508 leading-to local Wires 41,44a, of the B board.

At the keyboard A, a branch conductor 38 leads from the feed-wire 48through the pilot lamp 509 to earth, and When the controlling relay 26is operated during the use vot the sending apparatus A, a circuit iscompleted for lamp` 509, said lamp remaining illuminated during the useof the sending' apparatus. Similarly, at the keyboard B a pilot lamp 509is provided in a circuit closed by the controlling relay 26 of sai-dboard, when operated.

To summarize, in case the connecting-circuit l is taken tor use, andboth keyboards A, B l?, are idle,-the operator, observing the inertcondition ol both signal lamps 509 of the keyboards, will operate thekeyboard A, and upon the depression of key y19, such keyboard A will betied to the cord circuit I- by the locking circuit 18, 35, 37,495,including Vthe controlling relay 26 of keyboard A. The remainingconnecting circuits will thereupon be transferred to the keyboard B, acircuit being completed by the controlling relay 26 of the A board, fromthe tree pole of grounded battery-59 at connectingcircuit 1l, by Way ofvconductor 499, winding 497 ot relay 21 of the idle connectingl circuit,to earth through the armature 24 and back contact oit relayv 26 ofkeyboard A. This circuit will not be completed, however, at the cordcircuit l because the armature 500 ot relay 31 is attracted, removing`battery 59 from the battery reed Wire 499 of such connecting circuit.The circuit just traced includes Winding' 497 of relay 21 of connecting'circuit ll, which relay thereupon transfers at its armature 491 andfront contact the key 19 of such connecting circuit to the 'control otthe circuit leading to keyboard B, so that when said` second connecting'circuit is taken tor use and the operator depresses key 19 of suchcircuit, the controlling relay-26 oft the B board will be operated inthe circuit 22, 28, 496, 495, which includes also the relay 31 of suchconnecting' circuit, relay 31 in attracting` its armature 500completin'ga local lockingl circuit 501, including Winding 498 ot relay 21,armature `494and front contact of said relay, and-armature 500 and frontContact of relay 31, so that in case the'A board should complete -itsWork prior to the completer. operation ot 'the B board, and the initialcircuit includ-ing Winding 497 or relay v21 be broken by controllingrelay 26 oit the A board, the locking circuit 501 will maintain suchrelay 21 energized until the B board. completes its .ivorln whereupon.said locking,` circuit is broken. lt will be understood that While thekeyboard is in use, the lamp 509 will be displayed and the operator willknow that keyboard B is the one tire application 'of' our invention,yand' will firsts give af general outline of the mode ot operation ofsuch.` system.

In'f` a systemof,l for example,.100,'000 lines, there may be' provided`ten othces', at' each ofi' which terminates 100,000 lines.v Atv eachoiiice the lines mayl be arranged. in groups of? 300,1 although groupsof any number mightbeemployed. lV-ith such an arrangement there would'bey approximately 34 groups ot' 300 lilies aty each office or, to beexact, 33 groups4 of 300 lines and 1 group 0159100.y Each. connector hasa capacity of 300 lines and enough connectors are furnish'edf to handlethe calls for each group. .fllie operator' in` an. exchange answers acallin the usuali way by uniting her connecting circuit with"v the lineot the calling subscriber, andf after ascertaining the number ci" thecalled: party' and the exchange wherel the' line of such partyterminates, operates theidle sending apparatus, automatically' assignedTto her' connecting circuit, depressingthe key thereof, which'vrepresents the; desired office, and the thousands, hundfi-eds,` tens'and: units: digit keys representing the'number of; the linev wanted. Anoliice selector forms the terminals ofL the' connecting circuitVreferredf to, and. is operated by mechanism' controlled by the actuatedoffice key'tofunitef the: connecting circuit with an idletrunklinetl'eadin'g tothe desired oiice. Said trunk line" terminates at thedesired office in a primarysel'ector, which is a machine adaptedtoselect an` idle connector belonging to any one ofv thel thirty-fourgroups? A. translator is provided. in` connection wit-'h the-sendingoutfit to cause the thousands and` hundreds keys depressed to operatethe primary selector. and' pick out anidle oonnector'of' the groupdesired; The first 300 lines inthe exchange are numbered'OOO() to029'91These'numberswould beY reached by` pressing the"n`aught? button of thethousands-keysV` andthe 1?"01 2 button oi' the hundreds keys; There'visV a primary controller ati these-nd'ing outfit which controls theoperation of the primary' selector, thev tavobeing 'operatedt togetherin series. Thek translator is' pro-videdf with three brushes. The i'rstis associated with. the thousands andhundreds keys' and. arranged tostop the translator at a predetermined: point to cause thesecondi brushand the primary controller E whichare automatically brought intocircuitwhen the translator has stopped, to advance the primary selector intoposition` to'connect with thedesired. connector. The third`brush hasassociated therewith an auxiliary controller, andi said brush after theoperation?` of the primary controller automatically brings into play theauxiliary controller which advances the brushes of the selectedconnector to the proper hundreds zone ol3 the three zones of one hundredlilies each olE such connector. The depressed tens and units keys arenow brought successively into service,.the mechanism controlled therebyoperating the selected connector to cause the brushes thereof to unitewith the terminals ot. the desired line inthe selected Zone.

7e will now describe in detail the circuits and apparatus employed inconnecting thesubscriber shown in Fig. 1, whose line terminates atoltice C, with the line of the Subscriber No. 1132 shown in Fig. 4,whose line terminates at exchange D, using the connecting circuit I'.

The' line of subscriber 999, Fig. 1 extends in two limbs 1, 2, from thesubstation to the central otlice l where the line extends through theusual line signal apparatus to the'poles ol" a central battery. At thecentral oflice, the usual answering jack 3 is provided for the line, thethimble 4 of said jack vbeing connected with a conductor 5 which leadsthrough the usual cut-olf relay to the free pole of a grounded battery6. The operator is provided with an answering plug 7, with which touniteher connecting circuit with the calling line, the plug 7 and jack 3constituting a manual connection switch.

The link'conductors 8, 9 of the operators connecting circuit lead fromthe tip 16 and ring 11, respectively, of the answeriiig-plug` throughthe windings of the usual repeating coil between which is bridged abattery 12 in the usual manner, to the line brushes ol an officeselector 13, Fig. 2, a supervisory relay being included inlink-conductor 9 between the battery andthe ring ot the plugforcontrolling the usual supervisory signal. The sleeve 14 of the answeringplug is connectedl with a conductor 15, which leads to earth through thewinding of a relay 16. Said relay 16, whose circuit 5, 15 is completedupon the closure ot' the connection switch, is provided with an armatureconnected with the free pole of the battery 17, the front contact ofsaid armature being connected with a conductor 18 leading throughcontacts of the supervisory relays and the supervisory lamps to earth.

A key 19 is provided in association with the' conductors 8, 9 of theconnecting circuit, adapted, when operated, to unite the operatorstelephone set with the link conductors of the connecting circuit, andalso to close a pair ot' contacts, which control the placing of an idleone of the sending keyboards'A B into condition to serve said connectingcircuit. The anvil ofspring 20 is connected with a conductor 22 whichleads to the tree pole of' a grounded battery 58,

while the spring 2'0 is connected with a conductor 28 which leadsthrough the armature 29and back contact of relay 30, windings of relays31 and 26, armature 32 and back contact of relay 33 to earth. Thus whenkey 19 of connecting circuit l is operated, relay 31 thereof isenergized, as well as the controlling relay 26 of the idle sendingapparatus, in the present case, keyboard A.

Referring first to relay 31, its armature 34 is connected with aconductor 35 which leads through the contacts of a key 36 to conductor18, said conductor 18 being connected by the armature of relay 16 withthe free pole of battery 17. The front contact of the armature 34 ofrelay 31 is connected with a conductor 37 which leads through thewinding 38 of relay 30 to the armature 29 thereof. A locking circuit isnow completed for the relays 26 and 31 independent of battery 58, saidcircuit extending from the free pole of battery 17 by way of conductors18 and 35, armature 34 and front contact of relay 31, winding 38 ofrelay 30 to conductors 28, 495 and thence through the winding of relay26 of board A to earth. The armature 29 of relay 30 is now operated anddisconnects the key 19 from the circuit of the magnets 31, 26, so thatthe operator may at any time hereafter during the process ofestablishing' the connection, or during thel connection, listen in onthe circuit without interfering with the sending apparatus. r1`heresistance 23 is for the purpose of preventing a short circuit of therelay 30 when the armature 34 of relay 31 closes the branch throughwinding 38 of relay 30 from battery 17.

The relay 31 is also provided with armatures 39, 40. rlhe armature 39 isunited with a conductor 502, normally connected with wire 41, leading tothe sending apparatus A, and said armature is adapted when attracted toengage the member 42 of a pair of normally closed springs 42, 43,included in the strand 8 of the connecting circuit, to separate saidsprings, the spring 42 being connected with the portion of the conductor8 leading to the oiiice selector. ln like manner, the armature 40 isconnected with a conductor 504 normally connected with a common wire 44leading to the sending apparatus, A, said armature being adapted toengage the member 45 of a pair of springs 45, 46, which are normallyincluded in the ring strand 9 of the connecting circuit, to separatesaid springs, the spring 45 being connected with the portion of thestrand 9 leading tothe oflice selector. Armatures 39, 40, therefore,`

in their attractive movement, connect the strands 8, 9 of the connectingcircuit with the common wires leadingto an idle sending apparatus. Thearmature 500 in its attractive movement removes battery 59 from wire 499leading through relay 499.

The relay 26 of board A (Fig. 5) in operating, attracts its armature 47which is connected with the free pole of grounded battery 27, saidarmature being provided with a front contact connected with feed wire 48leading to the mechanism of the sending apparatus. The retaining magnetsof the sending apparatus are permanently connected with the feed wire48, and are operated the instant battery is applied by armature" 47 ofrelay 26 to the feed wire. The lamp signal 509 is also connected toearth, from the feed wire, and Vremains displayed while the sendingapparatus is in use. The sending apparatus A is now in operativecondition to serve the connecting circuit. rThe relay 26 of board A alsobrings about the switching of the remaining connecting circuits to the Bkeyboard, said relay 26 completing at its armature 24 and front contact,a circuit 499 associated with connecting circuit 1I, through the winding497 of relay 21 of said second connecting circuit, whereupon said relay21 switches the local circuits of the connecting circuit Il to thekeyboard B.

Operation of the oyftoe selector.

The office selector (Fig. 2) is provided with a shaft 50 arranged tohave two movements-a rotary movement to select a group of trunk linesleading to a particular office, or as in the present case a group oftrunk lines rleading to trunk selectors adapted to select an idleinter-office trunk, and a longitudinal or upward movement to select thefirst idle trunk line of such group. This shaft carries three brushes51, 52, 53, brushes 51 and 52 being connected with the strands 8, 9 ofthe connecting circuit, and the brush 53 being the local brush. Theshaft 50 is adapted to be rotated by means of the mag- .net 54 andmechanism controlled thereby,

and to be moved upward by a magnet 55 and its associated apparatus. Therelay 30 (Fig. 1) when operated, as before described, serves to placethe office selector in condition for operation. The armature 56 of relay30 is connected with the conductor 57, which leads from conductor 35 andbattery 17 through a winding of relay 30, armature 56 and its frontcontact, to the oliice selecy tor, and thence through the winding of arelay 61 and through a pair of contacts 62 closed by the shaft 50 whenin normal position, to earth. A circuit for re1ay'61 is thereby providedby conductors 18, 35, 57.

The said relay 61 when energized attracts its armatures 63, 64 and 65the armature 63 being connected with earth, and when attractedcompleting a locking circuit for the relay 61 independentl of contacts62. The armature 65 is connected with the free pole of a groundedbattery 67, said armature when attracted engaging its front contact fovA, We Will Whichis connected With a conductor 68 leading to earththrough the winding of the retaining magnet 66 of the shaft 50. Thearmature 64 of said relay is connected with Y the free pole of battery67 and the 'front contact of this armature is connected With a conductor69 Which leads through the contact springs 70, 71, associated With relay72, through the-winding of relay 73 to earth.

Relay 73 is provided with two armatures 74, 75, which with their backcontacts are normally included in the strands 8, 9 of the connectingcircuit, the armatures being connected directly with aportion of thestrands leading tothe plug 7. The armature 74 is adapted wheny attractedto engage a front contact Which'is connected with the conductor 7 6lleading; through the rotary stepping magnet 54y of the shaft 50, throughthe contact springs 77, 78', associatedv with relay 72, to earth.

'The varmature 7.5 of relay 73 when attracted is adapted to engageaffront contact connected With a conductor 79 which leadsfthrough `thearmature and front contact o'l" retaining magnety 66, relay 72, toearth. rlhe office selector is now in condition for' operation.

Turning now to thev sending apparatus V describe the means adapted to beset by the operator to actuate the office selector andvv select an idletrunk line leading to the exchange Where the called partys lineterminates. -In the present case the selector selects a trunk line whichleads toan idle trunk selector, said selector thereupon operating topick out an idle trunk line leading to the desired office. We Will'assume that the line of the party With Whom l. conversation is desiredterminates at oiiice D, and that his number at said office is 1132. Theoperator, therefore, after listeningin to ascertain the line desired andafter ascertaining ,by the condition of lamps 509, which sending.apparatus has been associated' Withv her connecting circuit I, inthe-.present case, keyboard A, depresses office key D, key I of thethousands keys, key I of the hundredskeys, key III of the tens keys,and: key Il of the .units keys.

The ofiice controller (Fig. 7) is provided` with Ia series of keys C, Detc., which are knownr as the Yoliice keys. Each key comprisesa plungeradapted when depressedV to be locked in such position under the controloia release magnet 80. Each plunger may carry a latch member,preferably, conical in form, adapted when the plunger is depressed, toengage the under side( of la latch bar to lock the plunger in itsdepressedv posit-ion, said: plunger, when the latch bar is opera-ted bymagnet 80` being restored by a suitable spring. Each A of said keys,when depressed, forces into electrical contact springs 82, 83, 84. The

spring 82 of each key is connected with the teed wire 48 previouslyreferred to, which is connected by relay 2G with the itree pole ofbattery 27. The spring 83 is connected with the conductor 85 which leadsto a terminal of a bank or' contacts 8G adapted to be engaged by thecontact arm 87. Said arm is provided with a steppingmagnet 88, theretaining magnet 89 of said contact arm being operated by current trom`the ieed wire 18, as previously described. Said contact arm 87 isconnected with a conductor 90 which leads to earth through the winding92 of relay 91.

The third spring 84 of each key is connecte-d with a conductor 93 whichleads through the winding of relay 94, springs 95, 90, associatedtherewith, to the ground contact of a pulsator 97, said contact beingarranged to be intermittently engaged by the grounded spring 98 of saidpulsator. The spring 99 ot said pulsator is connected with the free poleof grounded battery 100, the contact of said battery spring beingconnected with a conductor 101 leading to the armature 102 of relay 94.rThe lrout contact of said armature 102 is connected with a` conductor103 which leads through the winding of the stepping magnet 88 of contactarm 87, armature 104 and back Contact of relay 91, through the armature105 and back contact ci sluggish relay 10G to common wire 41.

Assume now that key D has been operated: Current will flow from the teedwire 48 by way of springs 82, 83, to the contact 86a in the bank 86.Battery will also be applied from the feed wire through the springs 82,83, 84, to conductor 93, and thence through winding of relay 94, springs95, 96, of said relay to earth by way of the pulsator when spring 98thereof engages its contact.. lV'hen such contact is made, relay 94 isenergized to attract its armatures 102, Armature 107 is connected toearth and engages contact spring 95, separating the same from its anvil96 and completing a locking circuit for rela-y 94 from the feed wireindependent of the pulsator. Arniature 102 in its attracted positionconnects the battery contact of the pulsator with conductors 101, 103.Impulses of' current now flow from the free pole of battery 100 overconductors 101, 103, winding of the stepping magnet 88 of contact arm87, over common wire 41, conductor 502, through armature 39 and spring42 of relay 31 (Fig. 1) to the tip-strand 8, armature 74 of relay 73 otthe ofiice selector (Fig. 2), conductor 76, through the stepping magnet54 ot the selector, springs 77, 78 ot relay 72 to earth.

The pulsator 97, as already described, when in position to close itsgrounded contact completes a circuit for the relay 94 rlhe steppingmagnets 88, 54, respond to-.

gether to the pulsatingl current and rotate the contact arm 87 of thecontroller and the shaft ofthe selector, respectively. When' the contactarm 87 of the oiiice controller reaches the contact point 86a, which isconnected through the lrey 0 with the feed Wire, and lthe shaft 50 vhasbeen stepped around so as to bring' its brushes in, front of the groupVof terminalsleading to trunk selectors adapted to pick o-ut idle trunklines leading to the desired oiiice,.current fleivs from the feed Wirethrough thecontact springs 82, 83, conductor 85, contact86, of the bank85, contact-arm 87, conductor 00, through the Winding 92 ofrelay 91 toearth. attracts its armature 10a, removing pulsating current from thestepping-magnets 88, 54. The armature 108 of rela-y 91 is connected toearth While its front contact is connected with conductor` 10Q/Whichleads through the Winding 110 of relay 91,

Windinglof'sluggish relay 106,to the feed The armature 108, therefore,When.

wire. attracted completes a locking circuit for relay 91, and also thecircuit of the sluggish relay 106.

Automatic' selection 5 1/ selector of 25mm/c i Zine.

\ ductor 14 by Wayl of conducters-85, 90 and 111 and thearmature 112 andback Contact. of relay 10G. This impulse passes- .through the armature40 and its Contact l5 ofrelay 31, (Fig. 1) strand 9 of the connectingcircuit to the office selector, thence through the armature 7 5 and itsfront contactof relay 73, conductor 79, armature and front contact ofretaining-magnet' 66, .Winding ofrelay 7 2 to earth. Relay/.7 2 isthereupon' operated and attracts its armatures 113, 114,- 115. Thearmature 114; is connectedwith Conductor 79, and is adapted whenattracted to engage a Contact connected With the condnctor which leadsto the free pole of battery G7, thereby completingna locking Relay 91 isthereby energized and circuit for the relay 72 from the free ypole ofbattery 67, armature 6a of relay 61, con ductor 69 to earth by Way ofarmature 114 and conductor 79.

The armature 113`of relay 72 is connected with a `conductor 116 whichleads to the front Contact of armature 117 of relay 73, said armature117 being connected with a conductor 118 leading to the local brush ofthe shaft 50. Said arma-ture 113 when attracted engages the spring 71connected directly to earth through rela-y 73, and connectssaid relaythrough its own armature 117 and front Contact With the localfbrush 53,for a purpose to be later explained.

The armature of relay 72 When attracted engages Contact spring 78,thereby opening the branch 7G containing` the stepping' magnet 54. Saidarmature is connected With a conductor 119 which leads through thelifting magnet ofthe selector, armature 120 and front contact of'relay73 to the battery Contact vof a pulsat-or 121. The shaft 50 now beginsits upward hunt for a-trunk line leading to a idle selector adapted topick outan idle trunkline leading to the office B. 1f the first trunkline is busy, battery will be present upon its local terminal 122, andWill maintain relay 73 ex-l cited in the path provided by Way ofconductor-118, armature 117 of said relay and its front Contact,conductor 116, armature 113, and front contact of ,relay 72, conductor`GSL to earth; the armature 120 of said relay 73 While attractedmaintains the circuit of the stepping magnet 55.

VVhlen, however, an `-idle trunk line is reached bythe bruslfies` on theshaft 50,v

there Will be no potential present at the local terminal 122 thereof andthe relay T3-Will be deprived of current, and will release all itsarmatures, armature 120 opening` the ,cir-v cuit-of the lifting magnet55; armatures 74,

75 restoring the continuity of the strand-S8,y

9` of the connecting. circuit-g. and the A-arrnature 117 breaking theconnection ofrel-ay 73 with the localbrush 53 and connecting at its backcontact conductor 118 leading from said brush with a conductor 123 leading to conductor 69, which is connected by arn'iature 64 of relay 61with-the free pole. of battery 67. rl`he brushes 51, 52", 53 of shaft50, now rest in en agement with contact termina-ls 124, 125, 122,respectively, connected with a trunlrline, leading to a trunk selector.V

Operation of t'rmic selector.

The trunk selector comprises a shaft 126l having one movement, arotarymovement,

three ed -With `a conductor of y'the -otliee selector, the :armaturesl133, 13.1, and .backcontacts .ofa relay 135 .being included in saidconductors 131, d132, Arespectively. The local trunlvterminal '122- ofthefselector is connected `.with 'the :conductor 137 which leadsthrough-fthe retaining -magnet 138 of the trunlrselector, vcontacts 139closed by the .selector sha'ftl126 :When'in normal position, :Winding140 of :relay 135 to earth, current :Ibeing zdelivered 'to saidconductor :137 from battery '67, whenfthe brush `engages said Contact`122 andthe relay 73 has restored itszarmature, as previously described,whereupon relay 135 and retaining magnet 138 are operated.

rlhe^retainingimagnet 138 in operating attracts-its armature andcompletes a locking circuit forr vitself :independent of contacts 139through its own armature, resistance 138a -and ground, the function ofthis resistanee `being to prevent the short-circuiting of .relay vRelay'135 Yin operating attracts its armatures 133, 1321, 141 and 1217.

,The armatures 133,1134When attracted-maintain .the selector brushes128, .129 dead duringselection. The armature 141 is lconnect- 142 whichleads through `the Winding i143 rof relay 135 yto earth. Said armature1:41 in its attracted position engages thefcontact spring 1114.1,.andseparates vthe same from lits normal Acontact 145, saidy springy T144being connected with a conductor 146 leading to fthe local .brush 130.Thearmature 1217 is connected with la conductor 148 v'which leads to thebattery contact of the pulsator 149, While the front contact of saidarmature `is connected .with

conductor 150 leading through the Winding ,y maintaining the 'relay 135energized. The

stepping 'magnet i127 'will thus Vcontinue to receive .current yandkwill advance the 'shaft another step, and so on until an idle trunkline is found, whereupon current .Will not be present upon theterminajl151, and relay 135 Willbe ldeprived Vof current, releasing its armaturesand .restoring -.the continuity 4of the talking conductors 131, '132,Which Were broken during :selection ato prevent disturbances; `openingat varmature .1457 the circuit of the stepping ymagnet 127; andVbreaking at :armature 141 :the lconnection of relay 135 Withxthe 'localbrush 130. Spring 145, which now rests inengagement with spring 1214,isfconnected with a conductor 152 leading .to conductor 137, which isconnected Withbattery 67 at the oliice selector, and a potentialistherebyapplied by Way of conductors 69, 123, 118, 137, 152, v146 tothe contact terminal 151=of the trunk 'line upon which :the selec-torAbrush 130 rests, .to lock out other trunk selectors'from the trunk lineselected. The'brushes 128, 129 `of the trunk selector .now rest =uponthe terminals of the limbs 152, 153, .-respectively, of a two-Wire trunkline leading 'to the ofiice D and the primary selector forming theterminal of suoli trunk line at said distant oiice.

@perm/fion of translatng machine and pw'- maryv se lector.

.Asbefore stated, the line with which connection .is1desired,is numbered1.132. Therefore the operator Ydepresses key lofthe 10005 keys 15.4, keyI of the 100s'keys 155, key 'III of the `lOs keys 15G, and key II of theunits keys 157. The 1000s and 100s keyscontrol the operationofthe-translator shown at the left in -which operates the Aprimaryselector 136 (Fig. 3), forming the terminal of the trunk fline at thedistant oiiice, to connect the trunk lines With an idle connectorof thegroup containing the desired number. The shaft 159 of the translator isarranged to 'have two movements, one in long steps under 'the control-of stepping magnet '160, and the other in short steps under the controlof magnet 161. The shaft carries .three brushes, the brush 162 beingadapted to co-operate with the depressed 1000s and 100s key,s,fand thebank of contacts '163 to stop the shaft at the proper point to cause thebrush 164 of the translator to apply :battery toa particular contact ofthe primary controller 165, and cause the same to operate inseries :withthe primary selectoruntilfthecontact arm 166 ofthe `primary controllerreaches-:the contactto vWhich battery has zbeen 4applied by brushI16.4,` and the primaiy;selector `reaches the group of trunksleadingftothe connectorsof thegroup wherein ,is locatedthecalled partys line, atwhich time :the :primary controller land iprimary selectorrare stopped,and the primary selector caused to locate an idle connector. Thefthirdbrush 167 of the'translator is provided with a 'bank of contacts 168which controlthe application of battery to a V.predetermined tpoint uponthe auxiliary controller -169, which isoperatedafter the primary.selector 'has located the connector to advance .the @brushes of suchconnector into the 'fproper bank of its three banks of 100 lines each.

Describing new Amore in detail the operation of the translatingmechanismand primary selector. The-relays 51-1 andl72 (Fig.

7) control the starting of the translating mechanism, said relays beingarranged to operate when the trunk selector has made connection with anidle trunk line leading to a distant oliice. Said relay 511 is includedin a conductor 170 leading from the front contact of the armature 105 ofthe relay 106, through contact springs 171 controlled by the armature173 of rel-ay 172, to the feed wire 48, the connect-ion of thisconductor at armature 105 of relay 1,06 with wire 41 being completedwhen the sluggish relay 106 is operated after the impulse is applied towire 44 to start the oiiice selector in its upward hunt for an idletrunk selector. r1`he circuit for relay 511 extends from the feed wire48 through the conductor 170 to conductor 41, thence through contacts39, 42 of relay 31, to link conductor 8, over trunk wire 131 to thetrunk selector, through the contacts closed thereby, to trunk wire 152leading to the distant office, where the same passes through one windingof a repeating coil bridged across the trunk conductors to a conductor174, which leads through the winding of relay 175, normally closedcontacts 17 6, 17 7 of a polarized relay 178, normally closed contacts179, 180 of said relay, normally closed contacts 181, 182 of relay 183,to trunk conductor 153, and thence to the primary selector, through thearmature 184, and back contact of relay 185, to a conductor 186, whichleads through contact springs 187 closed by the shaft of the selectorwhile in normal position, to earth. The relays 511 and 172 of thesending apparatus (Fig. 7) are sluggish in their operation to provide atime interval wherein the primary selector may get into condition foroperation. This is accomplished under the control of the relay 175associated with the trunk line at the distant office, which is in thecircuit just traced for the relay 511. Said relay 17 5 in attracting itsarmature, completes a circuit from battery 189 by way of conductor 190,which leads through the normally closed contact springs 191, 192 ofrelay 193, winding of relay 193, winding of the retaining magnet 194 ofthe primary selector, to earth, through the contact springs closed bythe shaft 195 of the primary selector when in normal condition. Therelay 193 and retaining magnet 194 are now energized and a lockingcircuit is completed for said relay and magnet independent of relay 175,said circuit extending'fro'm the free pole of grounded battery 196,conductor 188, through the contact springs 197,198, of relay 183,armature 199 of relay 193 (which is now in engagement with the contactspring 191, separating the same from its normal contact 192, anddisconnecting battery 189 from the circuit previously traced) throughthe winding of relay 193, and over conductor 190, through the winding ofthe retaining magnet and its armature 200 and front contact to earth.The armature 201 of relay 193, which is connected with the portion ofconductor 190 leading to the front contact of the armature of relay 175, in its attracted position opens the contact springs 202 which arenormally included in the trunk conductor 152, and engages the memberthereof which is connected with the portion of the trunk conductor 152,leading directly to the primary selector, the contacts 202 beingincluded in said conductor between the repeating coil and the selector.

The repeating coil serves to maintain the inductive continuity of thetrunk circuit while maintaining the circuit broken for directv current.r1`he two windings of the repeating coil connected with the portion Othe trunk circuit leading back to the trunk selector are included in abridge of said trunk conductor with a condenser, while the other twowindings of the repeating coil, which are included in the portion of thetrunk circuit leading to the selector, are included in a bridge of thetrunk circuit with a grounded battery 203.

'll he retaining magnet 194 when energized as, previously described,attracts its armature 204, completing a circuit from battery 205 by wayof conductor 206, through the contact springs 207, 2,08 of relay 209,winding of relay 185 to earth, said relay thereupon attracting itsarmatures 210,184, 211 and 212.

The armature 210 of relay 185 which with its back contact is normallyincluded in the trunk conductor 152, when attracted engages a frontcontact connected with the conductor 213 leading through a steppingmagnet 214 of the primary selector, contact springs 215 of relay 209 toearth. The magnet 214 is arranged to rotate the shaft 195 in thirty-foursteps to pick out the group of trunk lines leading to connectors servinga particular group of 300 lines. The remaining armatures of the relay185 bring into operative condition apparatus which will be hereinafterdescribed.

r1he primary selector is now in condition for operation, and sluggishrelay 511 of the sending apparatus (Fig. 7) has now operated to operaterelay 172, which in turn causes the deenergization of relay 511, saidrelay 172 locking itself up, and the combination of relays 511 and 172with the firstmentioned relay inert and the other energized, starts thetranslating mechanism. Relay 511 is provided with an armature 216connected with the feed wire 48, said armature when attracted,completing a circuit for the relay 17 2, armature 173, opening thecontacts 171 which are included in the circuit of the relay 511, and bymeans of said armature 173 and one of the members of the contacts 171,said relay 172 is locked to earth from the feed wire. rlhe armature 216of relay 511, which is connected with the feed wire, is provided withv aback contact connected with a conductor 217 leading through the armature218 and its front contact of relay-172 to the 1000s keys, and whenarmature 216 of relayV 511 is retracted, and armature 218 ofrelay 172 isattracted, current flows from the feed wire over conductor 217 throughthe armature 219 and back contact of relay 220 to the 1000s keys 154.(Fig. 6).

Each 100-0s key, when operated, is arranged to be locked in itsdepressed position under the control of a release magnet 221, asdescribed in connection with the ofliice controller; each key whendepressed forcing into electrical engagement contact springs 222, 223-and 224. Contact spring 222 is connected with the conductor 217, whichis united by the feed wire 48 to the free pole of battery 27, and saidspring in engaging its anvil 223 appl-ies battery to a thousands contactterminal in the bank 163 over which the brush 162 of the translatorsweeps. In the Vpresent case-calling line 1132-since key I is depressed,battery will be applied to the second thousands contact point 225 of thebank 163. It will be understood that 'the brush 162 normally rests onelong step fro-rn the first terminal which would be 0 or the firstthousands terminal. In the system sho-wn, in order that the brush 162may reach the second thousands contact point 225, it is arranged to takethree long steps. Between the first and second thousands contact pointsthere are ten intermediate contacts numbered from 0 to 9 inclusive; andthe advance of the brush to any of said intermediate contacts isdetermined by the 100s keys.

The spring 224 of key I, which is now in electrical engagement withsprings 223, 222, and thereby with battery 27, is connected with aconductor 226 which extends from all the springs 224 of the 1000s keys,through the winding of relay 22", contact springs 228 associatedtherewith, to the ground Contact of a pulsator 229; and when the groundspring of the pulsator engages said contact a circuit is completed forrelay 227 which draws up its grounded armature 230, said armatureengaging the member of spring 228 connected with the winding of relay227 and completing a locking circuit for said relay independent of thepulsator.

rlhe relay 227 is arranged to start the operation of stepping magnet 160of the translator, said relay having an armature 231, which, whenattracted, completes the continuity of a conductor 232 leading from thebattery contact of a pulsator 233, through the winding of relay 234,armature 235 and back contact of relay 236 to the conductor 41, which isconnected with the tip strand of the connecting circuit and on throughto the primary selector. lt will be noted that the locking circuit forrelay 227 is established by the pulsator 229 when in engage ment withits ground circuit so that the circuit of conductor 232 will lbecompleted before the pulsator 233 engages its battery contact, thusinsuring a complete initial impulse over conductor 232.

Vhen the battery spring of the pulsator 233 engages its contact, currentflows over conductor 232 through the relay 234, over conductor 41, tipstrand 8, trunk conductors 131, 152, through one winding of therepeating coil to conductor 174. thence through relay 175, contacts ofrelays 178 and 183, through the armature 184 and front contact of relay185, to conductor 237, through contacts 238 of relay 209 to earththrough the winding of said relay, this current being without effectupon said relay 209. Relay 175 in the circuit just traced re` sponds tosaid current, and in attracting its armature applies current frombattery 189 to conductor 190, and thence through armature 201 and one ofthe members of springs 202 of relay 193, to trunk conductor, 152, thencethrough armature 210 and its front contact of relay 185, conductor 213,rotary stepping magnet 214 of the primary selector, contact springs 215of relay 209 to earth, whereupon the stepping magnet 214 is operated torotate the shaft 195 one step. This advance of the primary selector' issimply to save time in the operation of the system.

The relay 234 in the circuit traced from the pulsator 233, responds tothe pulsations and applies current from battery 239 through the armature240 and its front contact of said relay 234, to the long step magnet 160of the translator, which ad vances the contact arm of the translator inlong steps. The relay 234 has an armature 241 also connected withbattery 239, said armature when attracted applying current from saidbattery to a conductor 242, which leads to earth through the steppingmagnet- 243 of the primary controller 165, to advance the arm 166thereof.

It will thus be seen that the translator arm, the contact arm of theprimary controller, and the contact arm of the primary selector, advancetogether until the brush 162 of the translator reaches the thousandspoint 225 of the bank 163 of contacts, at which time each of said armswill have taken three steps-the translator arm three long steps and theprimary selector arms three short steps each. The holding` or retainingmagnets of the translator and primary controller are permanentlyconnected with the i'eed Wire 48, and were operated the instant relay 26applied battery to the feed Wire, when the sending apparatus was takenby the connecting circuit for use.

Then the brush 162 ot the translator reaches the contact 225 it iindscurrent thereon, and said current passes through the brush 162 to aconductor 244, which leads through the armature 245 and back contact ofrelay 220, through the Winding 246 of relay 236, operating said relay236, which opens at its armature 235 and back contact the conductor 232,and the circuit betore traced, including the relay 234, pulsator 233,and the relay'175 at the primary selector, so stopping the movement ofthe contact arms of the translator, primary controller and primaryselector.

The translator is'now readyto respond to the control of the hundredskeys and seek the intermediate point beyond the contact 225 Where it isdesired to iinally stop the translator arm. ln tue present case, sincekey I of the hundreds keys is depressed, the second intermediate pointbeyond point 225 would be supplied with battery in the following manner:v

Relay 236 When energized, as above described, attracts its armature 247,which is connected With a conductor 248 leading through the relay 226 tothe feed Wire 46. rlhe front contact of armature 247 is connectedthrough a Winding of relay 236 to earth; and when said armature 247 isattracted, a circuit is completed for the relay 220 Which attracts itsarmatures 219, 245. Armature 219 when attracted connects conductor 217and battery 27 With conductor 249 leading to the springs 250 ot thehundreds keys 155. The armature 245 of relay 226 in its attractedmovement connects conductor 244 leading from brush. 162 with a conductor251 leading through the Winding of the relay 252 to earth. Brush 162 isnoiv dead since battery is removed by armature 219 ot relay 220 from the1666s keys, and so from contact 225. The three springs ot key I of the100s keys are now in electrical connection (key 1 being locked in itsdepressed position under the control ot a release magnet 42S) and themiddle spring 512 applies battery from spring 250 and conductors 249,217 to the second intermediate contact beyond point 225. The thirdspring 253 applies current by way of the springs 250, 512 and conductors249, 217, to conductor 254 leading through Winding of relay 255, toearth; said relay 255 in attracting` its armature completing thecontinuity ot a circuit 513, which extends from the battery contact of apulsator 257, through the Winding ot the short-step magnet 161 of thetranslator, through the armature and back contact ot relay 252 to earth.The pulsator 257 applies current through the circuit just traced tooperate the stepping magnet 161 and advance the shaft in tivosl'iort-steps, until the brush 162 of the translator rests upon thesecond intermediate point beyond a contact 225, at which time currentwill tloiv by Way ot brush 162 and conductor 244 through the armature245 and front contact of relay 220, conductor 251, to earth throughrelay 252, which Will attract its armature 258 and open the circuit ot'the pnlsator 257 and the stepping magnet 161 of the translator, leavingthe shaft 01:' the translator three long` steps and tivo short stepsfrom its normal position.

Primary controller.

The primary contro-ller in an exchange such as We are describing, Wherethe lines are arranged in groups or' three hundred, would havethirty-tour contact points, each point representing a group contactpoint of a primary selector, which in like manner would have thirty-tourrotary steps to engage thirty-'four terminals. From each terminal ot theprimary controller a conductor runs to three contact points strappedtogether, over which the second brush 164 of the translator is arrangedto sweep, said brush being adapted after the translator has been broughtto a predetermined point under the control of the 1006s and 106s keys,to apply battery to a certain group of strap contacts to stop thecontroller and selector, when the selector is advanced to the group ottrunk lines leading to the connectors serving the group of lines inwhich the called partys line is located. rllhe operation ot the primarycontroller and selector is automatically effected immediately upon thecompletion of the movement of the translator. The relay 252 which wasoperated the instant the translator brush landed on the secondintermediate point in attracting its arma-ture 262 applied current froma positive battery 263 to conductor 264 leading to the brush 164 whichnow rests upon the setot strapped contacts connected with the fourth.contact 265 in the bank ot contacts ot the primary controller 165.

It should be remembered at this point that the primary controller andprimary selector follow the long steps of the translator brush, so thatthe arm 166 ot the primary controller and the brushes on the shaft 195o't the primary selector rest on their third group terininals. Thisarrangement is simply to save time in setting up Ithe connection.

The. armature 266 of relay 252 which Was operated when the translatorcompleted its movement, serves to start the primary controller andselector, said armature 266 being connected with a grounded contact oithe pulsator 267, the front contact of said armature being connectedWith a conductor 268 leading through contacts 269 of the relay 270 andWinding of said relay to the feed Wire 48. The instant the ground springof the pulsator 267 engages it-s contact, a. circuit is completed frombattery 27 over the feed Wire 48, conductor 268, through relay 270,armature 266 and front Contact of relay 252, to earth; and the relay 270in operating attracts its armature 271 which separates springs 269,engaging one of such springs to complete a locking circuit of suolirelay 270 fromrthe feed Wire independent of the pulsator.

An armature 272 is provided for relay 270 which is connected With thebattery contact of a pulsator 278, the front contact of armature 272being connected With a conductor 274 leading through a relay 275,arnrature 276 and back contact of relay 277, to conductor 41, whichleads to the tip strand 8. Relay 275 controls a' circuit from battery278 through the stepping magnet 248 of the controller. The pulsator 27 3applies current through the relay 275 and out over conductor `41,tip'strand 8, trunl conductors 181, 152, to the distant office, andthence through conductor 174, relay 175, contacts 181, 182, of relay 188to trunk 'conductor'. 158, thence through conductor 237, and relay 209,to earth, this current,

-hoivever not afiectino' the rela 209. The

relay 175 responds to the: impulses in the circuit traced, and completesa circuit from battery 189 over conductor 190, armature 201 of relay198, and one of the springs 202 to the trunk conductor 152, and thencethrough the armature 210 of relay 185, conductor 218, stepping magnet214 of the primary selector, contacts 215 of relay 209 to earth. Therelay 275 associated with the primary'controller and included in thecircuit of pulsator 27 8 above traced, makes and breaks the circuit ofthe stepping magnet 248 of thecontroller. The stepping magnet 248 of thecontroller and 214 of the selector, now rotate their respective contactarms until the contact arm 166 of the controller reaches the fourthcontact in its path, which is connected by the brush 164 and conductor264 with positive grounded battery 268, at which point current flowsfrom said battery through the arm 166 of the Ycontroller and theconductor 269 leading from said-arm through a Winding of relay 277 toearth, Relay 277 now operates and attracts its armature 276, opening theeircuit from the pulsator 278 through the relay 275 of the primarycontrollerand the relay 175 at the distant office, said relay 175controlling the circuit thro-ugh the stepping magnet 214 ofthe primaryselector. Said relayV 277 also draws up its armature 280, completing alocking circuit for itself,

which extends from the feed Wire 48 through sluggish relay 281, Windingof relay 277 to earth. The. brushes on the shaft 195 of the selectorhave non' reached the fourth. group of trunk lines, which lead toconnectors adapted t0 reach the line with which connect-ion is desired.

Automatch select/0n of MZ@ trunk of .scecfoi The attraction of armature276a of relay 277 completes the continuity of a conductor 282 whichleads from the conductor 269 (Fig. 6) between the brush 166 and relay277, through the armature 270A1 and front Contact of relay 277 armature283 and back contact of sluggish relay 281, to conductor 44, and beforethe sluggish relay 281 has had time to operate, an impulse from positivebattery 263 flows by Way of conductor 264, brush 164, Contact arm 166,and its fouri h terminal, conductors 269 and 282, conductor 44, to thering strand 9 of the connector circuit, trunk conductors 182, 158,through a lower winding of the repeating coil, to conductor Y springs285, 286, Winding of the polarized relay 178 to earth. Said positivecurrent causes the relay 178 to tilt its armature in a contra-clockwisedirection, whereupon spring 177 of said relay is separated from itsanvil 176 and thrown into engagement With a contact 287 connected withthe .free pole of grounded battery 288; current thereupon flowing frombattery 288 through the springs 287, 177, conductor 174, contacts 181,182 of relay 188, trunk conductor 158, armature 184 and front Contact ofrelay 185, couductor 287, springs 238 of relay 209, and Winding of saidrelay to earth.

Relay 209 is now energized and draws up its armatures 289, 290, 291.r1`he armature 290 is connected with conductor 206 which leads from thebattery 205; and said armature when attracted separates springs 288,engaging the member thereof leading directly to earth through relay 209,and completing a locking circuit for said relay independent of relay178, which by this time has been deprived of current owing to theoperation of the sluggish relay 281. Arniature 291 of relay 209 isconnected with a conductor 292 leading through the lifting magnet 298 ofthe primary selector, armature 212 and front contact of relay 185 to thebattery contact of a pulsator 294. And said armature 291 when attractedis adapted to separate springs 215, breaking the coutinuity of conductor218 connecting the ro tary stepping magnet 214 with trunk conductor 152,and to engage the grounded contact spring of said pair of springs 215 tocomplete a circuit for the lifting magnet 298 and the pulsator 294. Saidmagnet 293 is adapted to step the shaft 195 up in search of a trunk lineleading to an idle connector 284, which leads through the contactadapted to serve the fourth group of three hundred lines in which theline desired, number 1132 is to be found.

The armature 289 of relay 209 is connected with a conductor 296 leadingthrough the armature 211 and front contact of relay 185 to the localbrush 297 of the primary selector; said armature 289 when attracted isadapted to separate springs 207, 208 included in the circuit frombattery 205 with relay 185, and to engage the spring 208, therebyconnecting said relay 185 through its own armature 211, and frontcontact with said local brush 297.

Now when the selector has been given one upward movement to bring itsbrushes into engagement with the terminals of a trunk line leading tothe lirst connector of the fourth group, if that connector is busy, thelocal brush 297 of the trunk line leading to said connector will havepotential thereon from the local terminal 298 of said trunk, and currentwill iow through the local brush 297, armature 211 and front contact ofrelay 185, winding of relay 185 to earth, maintaining` relay 185energized. Relay 185 in turn will maintain the circuit of the upsteppingmagnet 293 intact, and the said magnet 293 will lift the shaft 195another step, and so on until a trunk line leading to an idle connectoris reached, when no current will be found upon the local terminal 298 ofsuch line, and relay 185 will be deprived of current, releasing itsarmatures. rlhe armatures 210, 1811-, in retracting restore thecontinuity of the trunk conductors 152., 153; the armature 212 opens thecircuit of the 11p-stepping magnet 293, and the armature 211 opens theconnection of relay 185 with the local brush 297, and. engages its backcontact connected with a conductor 299 which leads through armature 204`and front contacts of the retaining magnet 194, to the free pole ofbattery 205, thereby placing by way of local brush 297 a test potentialupon the multiples of the local trunk terminals 298.

The line brushes of the shaft 195, which form the terminals of trunkconductors 152, 153, arenow in engagement with terminals of the trunkline leading to an idle connector adapted to reach line 1132, saidbrushes engaging terminals connected with concluetors 300, 301,respectively, while the local brush 297, which is connected with thefree pole of 'battery 205, applies battery by way of terminal 298, tothe local trunk conductor 302 which leads through the contact springs303, 304 of a busy test and lock-out relay 305 of the selected connector(Fig. 4l) winding of the retaining magnet 30G of the coni nector,through contact springs closed by the shaft 307 of the connector when inits normal position, tol-earth. The retaining magnet 306 thereuponattracts its armatures Dit@ 307, 308, armature 307a completing a lockingcircuit for the retaining magnet 30G, independent of the springs whichare separated while the connector shaft 307 is away from normalposition.

The auxiliary controller.

After the primary selector has selected an idle connector, the thirdbrush 167 (Fig. 6) of the translator and mechanism ass ciated therewith,is arranged to operate the conneetor to move the brushes on the shaft307 thereof into the zone or ybank of contacts in which is located theterminals of the called partys line. To this end in calling line 1132,the auxiliary controller 169 is arranged to cooperate with the brush 167of the translator' to move the brushes of the connector into associationwith the third bank of contacts in which is located the terminals ofline No. 1132 with which connec-l tion is to be established. A conductor311 leads from the wire 259 which is now supplied with current frompositive battery 203 by way of the primary controller, to the brush 167of the translator which now rests upon a second intermediate contact 310beyond the second tens contact of the set or bank of contacts 168 overwhich the brush 167 sweeps, said second intermediate contact beingconnected with a conductor 312 which leads to the last contact terminal313 upon the auxiliary.controller 169, said Contact 313 being includedin a bank of contacts adapted to beengaged 'by the contact arm 311 ofthe controller. The intermediate contact points of the bank 168 aredivided into groups of three; the first contact of each grouprepresenting the iirst zone of a connector, being dead; the secondContact of each group representing the second zone, being connected witha conductor 312 to apply battery to the tenth contact point of thecontroller, while the third Contact of each group, representing thethird zone of a connector, is connected with a conductor 312 leading tothe twentieth Contact of the controller.

rhe auxiliary controller has twenty contacts in its bank, and thecontact arm 3A is arranged to be movedl with the connector brushes toplace said connector brushes into operative connection with the properbank of contacts. Thus if the line wanted were in the iirst bank of contcts, the auxiliary controller would not operate, since the conH nectorbrushes are normally in operative relation to said first bank and thebrush 167 would rest upon dead contact. However, if the line desiredwere in the second bank of contacts, potential would be applied by thetranslator brush 167 to the tenth con- 'act of the auxiliary controller,and the cony troller arm would advance with the connector brushes tensteps, when both would be stopped, leaving the connector brushes in

